using UnityEngine;

public class CameraController : MonoBehaviour
{
    public Vector2 Margin, Smoothing;
    private Vector2 first = Vector2.zero;//鼠标第一次落下点
    private Vector2 second = Vector2.zero;//鼠标第二次位置（拖拽位置）
    private Vector3 vecPos = Vector3.zero;
    private bool IsNeedMove = false;//是否需要移动

    private Camera m_camera;


    private void Awake()
    {
        m_camera = GetComponent<Camera>();
    }
    public void Start()
    {
        first.x = transform.position.x;//初始化
        first.y = transform.position.y;

    }

    public void OnGUI()
    {
        if (Event.current.type == EventType.MouseDown)
        {
            //记录鼠标按下的位置 　　
            first = Event.current.mousePosition;
        }
        if (Event.current.type == EventType.MouseDrag)
        {
            //记录鼠标拖动的位置 　　
            second = Event.current.mousePosition;
            Vector3 fir = m_camera.ScreenToWorldPoint(new Vector3(first.x, first.y, 0));//转换至世界坐标
            Vector3 sec = m_camera.ScreenToWorldPoint(new Vector3(second.x, second.y, 0));
            vecPos = sec - fir;//需要移动的 向量
            first = second;
            IsNeedMove = true;

        }
        else
        {
            IsNeedMove = false;
        }

        if (GUI.Button(new Rect(0, 0, 100, 30), "screen size"))
        {
            Debug.Log($"orientation={Screen.orientation} width = {Screen.width} height={Screen.height}");
        }

    }
    public void Update()
    {
        if (IsNeedMove == false)
        {
            return;
        }
        var y = transform.position.y;
        y = y + vecPos.y;//向量偏移
        //限制摄像机移动
        y = Mathf.Clamp(y, -49, 50);
        transform.position = new Vector3(transform.position.x, y, transform.position.z);
    }

    
}